Roll-bar for pulp-engines



(No Model.)

J. H. HORNE. ROLL BAR FOR PULP ENGINES.

No 520,960. Patented June 5, 1894.

UNITED STATES PATENT OFFIcE.

JOHN H. HORNE, OF LAWRENCE, MASSACHUSETTS.

ROLL-BAR F'OR PU LP-'-ENG|NES.

SPECIFICATION forming part of Letters Patent No. 520,960, dated June 5,1894.

Application filed January 20, 1894. Serial No. 497,502. (No model.)

1 0 all whom) it may concern:

Be it known that I, JOHN H. HORNE, a citizen of the United States,residing at Law: rence, in the county of Essex and State ofMassachusetts, have invented certain new and useful Improvements inRoll-Bars for Pulpthey operate to such a consistency as will permit itto be converted into a sheet.

The drawings represent in Figure 1 a perspective view of a roll-barembodying my invention. Fig. 2 is a cross-section of a roll in part witha number of bars in position. Fig.

paper web or '3 is a cross-section of a single beveled bar.

Fig. t is a modified form of a bar.

This invention, as before premised, relates to the manufacture of barsor blades for use in the rollswhich form an essential part of allpaper-pulp engines, and it may be considered as relating to andconstituting an improvement upon an invention described under UnitedStates Letters Patent No. 253,606, and issued in my name on July 14,1882. The primary feature in said invention and patent consisted inconstructing a bar in whichthe metal composing it was disposed equallyof a median line drawn centrally and longitudinally of said bar.Furthermore in dividing the side surfaces into two portions which slopetoward the opposite bounding edges of the sides. In other words the barwas made with a double bevel, which not only enabled a roll to be madeinterchangeable from a right-handed to a left-handed engine, butlikewise assisted in maintaining the wooden strips or wedges, which areemployed in looking said bars fast to the roll, in place. In the activeoperation of the rolls, the knives are coutinuallysubj ected to suddenlateral shocks or blows dueoto the passage of hard material between theroll and the bed-plate in the act of comminuting the stock, wood-pulp,or other material circulating about in the engine. These repeated blowsserve to start the wood filling, and when this occurs the bars arefrequently bent and become loose; the roll is then in need of repairs,which necessitates the stopping of the engine'with loss of time,

while the producing capacity of the mill is reduced.

The object of my invention is to produce a roll-bar of such form, thatafter the wooden filling or wedges are driven home positive engagementshall occur between the bar and the wedge, in'order to prevent thewedges ever starting from their places under any ordinary shocks orblows which may occur when the roll is in use. To this end I have showna roll-bar at 2, as made from steel which is to be manufactured instrips, andthen cut into suitable lengths. This bar, as shown incrosssection has its thickest part preferably to one side of thelongitudinal center andis formed with a double bevel; the lower orlonger beveled surface 3 being inserted in the roll, the

upper and shorter surface 4 projecting beyond the roll proper andserving to act as the cutting edge. Between the blades are insertedstrips'or wedges of wood adapted to extend longitudinally of saidblades. The-upper series are indicated at 5, the lower series at 6. Inorder to prevent these wedges from becoming loose, I roll, out, press orotherwise form upon one side of the bar, or that part contiguous to thewedges, a step surface 7. This surface is made up in thepresentinstan'ce of portions 8, 9, located in different planes andseparated by shoulders 10, 10, the height of the shoulder representingthe difference in the position of the planes. Hencewhen the wedges aredriven into place, the woody fibers will yield suffioiently to admit ofa snug fit being made, the wedges being given a taper approximating thegeneral shape of the space between the bars. After said wedges have beendriven into place the natural expansion of the wood due to thepresencelof moisture will cause the wood to conform exactly to thestepssurface, and in this way fill compactly the space between the bars.WVhen this expansion has occurred,

the shoulders 10,10, then act as stops to prevent the wedges frombecoming loose or drawing out, since the bars now have positiveengagement with the wedges.

In the operation of keying the bars into the roll, I arrange said barsas shown in Fig. 2, that is in this particular instance only one half ofthe lower side portion of each bar is provided with a step surface,hence the next adjacent bar is positioned with the smooth lower sideportion opposite the step-surface of the other bar, since I find inpractice that a step-surface on one bar is sufiicient to hold the wedgesbetween any two bars firmly in place. The bars are to be secured to theroll in any suitable manner now practiced, preferably however, hoops(not shown) are shrunk on the ends of the roll, while slots are cut inthe extremities of the bars. Thus by causing the bars to engage thehoops said bars are fastened strongly to the roll and are then wedged inthe manner set forth. However both the lower beveled surfaces may beformed with step-surfaces, and still be within the gist of my invention,since I do not wish to be limited to the precise form of thestep-surface, or whether it is applied to one or both sides of a bar.

In Fig. 3 I have shown my invention as applied to a single bevel bar 2',one side being a continuous plane surface, the upper beveled surface isindicated at 4', while the lower beveled surface is formed with a stepportion 7. In some instances, as shown in Fig. 4 the lower body of thebar, or that portion which is embedded in the roll, in contradistinctionto the projecting part or cutting portion has no taper, but is ofrectangular shape in cross-section, the step portion being raised uponit. In this particular class of bar, it is found much more difficult toretain the wood filling, since the angle between the diverging sidefaces of adjacent bars is much sharper, and hence my invention 1speculiarly applicable.

What I claim is 1. Abar for pulp engines having a portion of its sidesurface divided into a number of separate surfaces located in differentplanes to create successive shoulders, which extend inwardly into thesubstance composing the bar, substantially as and for the purposesexplained.

2. A bar for pulp-engines having a portion of its side surface dividedinto steps, and made up of a number of plane surfaces extendinglongitudinally of the bar, and a number of shoulders or risers whichseparate the several plane surfaces, the risers not projecting beyondthe general side surface of the bar, substantially as set forth anddescribed.

3. A bar for pulp-engine rolls having its' opposite sides tapering froma longitudinal line central or thereabout oppositely to each edge, andhaving a portion of its surface formed with a series of steps, whichextend lengthwise of the bar, substantially as specilied and stated.

4. In combination with a roll, a series of bars, a series of planesurfaces longitudinally of each bar, a series of steps which separatethe several surfaces, and wedges adapted to be inserted between theindividual bars and engage the steps upon the bar, substantially as setforth.

In testimony whereof I afiix my signature in presence of two witnesses.

JOHN II. HORNE.

Witnesses:

II. E. LODGE, FRANCIS C. STANwoon.

